What is Grey Literature?

Grey literature is generally material not published commercially or indexed by major databases.

A more complete definition is information "produced on all levels of government, academics, business and industry in electronic and print formats not controlled by commercial publishing i.e. where publishing is not the primary activity of the producing body." (http://www.greynet.org/)

Sources of Grey Literature

Deep Web Searching

Institutional Repositories

Reports and Research, Theses/Dissertations, Clinical Trials

The Invisible Web

(Only SOME of the Invisible Web [grey box] material is available via UW Libraries databases and sites listed on this guide.)
Data from P. Gil, "What is the invisible web?" Dec. 2010. Schematic by N. Tann, Goshen College, March 2011.

Deep Web

The Deep Web, also known as the Invisible Web, is a portion of the web not reached by standard search engines, such as Google and Bing. Less than 10% of the web is indexed by search engines, with the remaining 90% of web content called the Deep Web. It is estimated to be 2-500x bigger than the visible web.

Institutional Repositories

An Institutional Repository is a virtual space where a university or research institute collects and preserves its research and findings. Information in Repositories is considered grey literature since these resources are not traditionally published.

ResearchWorks at the University of Washington: digital repository of articles, technical reports, dissertations, datasets, images and other file types produced at UW by faculty and researchers.